Mercury-vapor rectifier.



INVENTOR ATTR'NEY P. CONRAD. MERCURY VAPOR REGTIFIER. APPLIOATION FILED sEPTLzo, 190e.

Patented Sept 6, 1910.

n sumssnm 1.

WITNESSES @msm 1H: Noam: PsYsms cal, wnmncrnn, n, c

P. CONRAD. MERCURY VAPOR BEGTIFIER. APPLIUATIOH FILED SBM. zo, 190e.

Patented Sept. 6, 1910.

2 SHEETS-SHEET 2.

.LAAAAAALAAAA ...All

vvvvvvvvvvv vvvvvv-vvvvv n INVENTOR d Wvg WITNESSES: /@W

ATTORNEY UNITED STATES PATENT OFFICE.

FRANK CONRAD, OF SWISSVALE, PENNSYLVANIA, ASSIGNOR TO WESTINGI-IOUSE ELEC- TRIO & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

MERCURY-VAPOR RECTIFIER.

Specification of Letters Patent.

Patented Sept. 6, 1910.

Application filed September 20, 1906. Serial No. 335,526.

To all whom it may concern:

Be it known that I, FRANK CONRAD, a citizen of the United States, and a resident of Swissvale, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Mercury- Vapor Rectiiiers, of which the following is a specification.

My invention relates to rectifiers for alternating currents, and particularly to those in which a vapor is utilized as the rectifying agent.

The object of my invention is to provide a device, of the character indicated, of such a structure and to so arrange the circuit connections thereof that starting of the rectifying process may be effected readily and efiiciently.

Considerable difficulty has been heretofore experienced in the starting of mercury vapor converters or rectifiers, the means usually employed for` causing and facilitating starting comprising a pair of auxiliary positive terminals that are disposed in close proximity to the negative terminals and that are connected to a transformer winding, the middle o-r an intermediate point of which is connected through a resistance to the direct current distributing circuit. Starting of the rectifying process is effected by tilting the device and thereby causing some of the mercury to be spilled, from the projections or receptacles in which the auxiliary positive terminals are located, into the receptacle for the mercury that forms the negative terminal. The sparking which is thus caused to occur overcomes the initial high resistance of the device, and the circuit is soon established between the main positive terminals and the negative terminal of the device. It has been found, however, that starting is often delayed, because, at the instant of establishment of the circuit between the auxiliary positive terminals and the negative terminal, the currents do not agree in direction with the impulses in the main circuit of the device. According to the present invention, starting of the rectifying process may be effected without such delays as are incident to the operation of prior devices.

Figure 1 of the accompanying drawing is a sectional view of a device that is constructed in accordance with my invention, the circuit connections and arrangements being shown diagrammatically, and Fig. 2 islv a similar view illustrating a modification of the invention.

The device comprises a receptacle 1 from which the air has been 'exhausted and that is provided, at its lower end, with two branches or protuberances 2 and 3 into which circuit terminals t and 5, respectively, project. The receptacle is provided, at its upper end, with two inwardly extending branches or arms 6 and 7 through the ends of which positive conductors S and 9, respectively, project, the conductors being provided with cup-shaped terminals 10 and 11. The branches 6 and 7 are provided, in the interior of the receptacle, with hook-shaped tubular extensions, as is usual in such devices. The cupshaped terminal pieces 10 and 11 form the positive terminals of the device and are connected, respectively, to the terminals of secondary winding 12 of a transformer 13, primary winding 14k of which may be connected to any suitable alternating current circuit. The middle or other suitable intermediate point of the secondary winding 12 is connected to a conductor l5 of a distributing circuit that may sup ply arc lamps 16 or other suitable translating devices. The protuberances 2 and 3 are filled with mercury which forms two negative terminals for the device, and these terminals may be connected respectively to the terminals of an auxiliary secondary winding 17 for the transformer 13, the middle or other suitable intermediate point of which is connected to distributing circuit conductor 18. Suitable ohmic resistances 19 and 2O are interposed respectively between the negative terminals of the device and the terminals of the transformer winding 17, and an inductive resistance or choke coil 21 is placed in the conductor 18.

In order to start the device, the receptacle 1 should be tilted so as to spill some of the mercury from one of the protuberances 2 or 3 into the other. The arcing-which ensues overcomes the initial high resistance of the device, and a circuit becomes established between positive terminals 10 and 11 and the one or the other of the negative terminals 2 and 3, it being immaterial which protuberance forms the negative terminal during continuous operation. Direct current is then caused to traverse one-half of the auxiliary winding 17 of the transformer in being supplied to the distributing circuit conductor 18. The resistances 19 and 2O serve to limit the amount of current which may traverse the local circuit that is established when the mercury is spilled from one of the protuberances 2 and 3 to the other, but since only one of the resistances is in circuit during continuous operation, no considerable energy losses result therefrom. The choke coil 21, because of its inductance, serves to prevent stopping or interruption of the rectifying process, and to be most effective, should be placed in series with the conductor that is connected to the negative terminals of the device, as indicated.

Instead of employing the resistances 19 and 2O to limit the amount of current in the local circuit established when arcing occurs between the negative terminals, a transformer 23 of poor regulation may be interposed between the negative terminals of the device and auxiliary secondary winding 24 for the main transformer25, the middle or another intermediate point of secondary winding 26 of which is connected to direct current supply conductor 27 as shown in Fig. 2.

I claim as my invention:

1. The combination with a current-rectifying device comprising a receptacle having but two adjacent protuberances, of a conductingfluid contained in the protuberances and constituting negative terminals, positive.

terminals that project into the receptacle, and sources of alternating current connected, respectively, between the protuberancesv and between the positive terminals and having neutral points connected to the distributing circuit.

2. The combination with a current-rectifying device comprising a receptacle having but two adjacent protuberances, of a conducting fluid contained in the protuberances and constituting negative terminals, positive terminals that project into the receptacle, and transformer windings connected, respectively, between the protuberances, and between the positive terminals and having intermediate points connected to a distributing circuit.

3. The combination with a current-rectifying device having two positive and two negative terminals, of sources of alternating current connected, respectively, between the pairs of positive and negative terminals and having neutral points connected, respectively, to a distributing circuit.

4. The combination with a current-rectifying device having two positive and two negative terminals, of sources of alternating current connected, respectively, between the pairs of positive and negative terminals and having neutral points connected, respec-` tively, to a distributing circuit, and currentlimiting means interposed in the circuit be,- tween the negative terminals and the corresponding source. Y

5. The combination with a current-rectifying device having two positive and two negative terminals, of transformer windings connected, respectively, between the pairs of positive and negative terminals and having A transformer winding.

7. The combination with a current-rectifying device comprising a receptacle having but two adjacent protuberances, of a conducting fluid contained in the protuberances and constituting negative terminals, positive terminals that project into the receptacle, sources of alternating current connected, respectively, between the protuberances and between the positive terminals and having neutral points connected to the distributing circuit, and resistances interposed in the connections to the'protuberances. e

8. The combination with a current-rectifying device comprising a receptacle having but two adjacent protuberances, of a conducting fluid contained in the protuberances and constituting negative terminals, posie tive terminals that project into the receptacle, two transformer windings connected,`

tember, 1906.

FRANK CONRAD. Witnesses: OTTO S. SCHAIRER, BIRNEY HINEs. 

